Mind & Body

An 80-Year Harvard Study Found the Greatest Predictor of Happiness in Later Life

What is happiness? It's one of those questions that science just can't answer. Or at least, that's what we would have thought. But since 1938, a group of researchers at Harvard has been working away at the problem through a generation-spanning study of several hundred American men.

Happiness Is a Warm Dataset

Welcome to the Harvard Study of Adult Development. It's actually a combination of two different studies: the Grant study, which focused on 268 Harvard male graduates from the classes of 1939–1944; and the Glueck study, which focused on 456 men who grew up in inner-city Boston. Its purpose? To discover what social, biological, and personal factors are the best predictors of happiness in later life.

Over the past eight decades, the 700+ participants have kept in touch with the study via a series of regularly scheduled check-ins. Every two years, the men were (and are) asked to complete a questionnaire about their physical and mental health, the state of their marriage, their career, and eventually their retirement. Every five years, they submit health information. And every five to ten years, some of the men sit for more in-depth interviews about their overall happiness and the state of their lives.

In the words of the study's longtime director George Vaillant, all that data can be boiled down to five words: "Happiness is love. Full stop." It's true; the one variable that predicted happiness in late life better than anything else was the number of so-called "warm relationships" the man had. That's true throughout his life, by the way — men who had warm relationships with their mother in childhood were found to earn an average of $87,000 more per year than others, and those who were close to their fathers showed higher satisfaction in late life. But it was actually relationships from around age 47 that proved to be the best predictors of happiness in the 80s and 90s.

Related Video: The Capacity of Intimate Relationships Predicts All Aspects of Life

Then Comes the Baby in the Baby Carriage

Now that a full generation has nearly passed since the first study began (the surviving participants from the earliest years are all centenarians by now), the study has begun to expand its focus. The 2nd generation study has a similar 70-year mission, but its subjects are the children and step-children of the men from the original study. These participants are getting a late start on the study compared to their fathers, but with the data gathered from the past century, they'll be able to paint a more complete picture of happiness in the modern world.

Mapping happiness to your personal relationships is one thing, but now the study can expand to include more remote factors, such as your parents' happiness and the strength of their relationships. We're finding out that happiness grows when we're all closely connected, and that means your happiness might have more to do with the happiness of others than you previously thought.

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You can hear George Vaillant's inspiring thoughts on the men of the happiness study right now by picking up his book, "Triumphs of Experience," on Audible (it's free with a trial membership). We handpick reading recommendations we think you may like. If you choose to make a purchase through that link, Curiosity will get a share of the sale.

Written by Reuben Westmaas April 13, 2018

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